The present invention relates to an optical communication network node, and more particularly to an optical communication network node utilizing an asynchronous transfer mode (referred to as an ATM, hereinafter) technology and an optical wavelength dividing multiplex technology.
In recent years, together with improvement of a transmission band due to development of an optical fiber transmission technology, expectation to a broad band ISDN (referred to as a BISDN, hereinafter) has been raised, in which these kinds of communication services, such as voice, a data and an image, are contained together and which provides the services to a member. There is an ATM technology as a network technology indispensable for realizing this BISDN. The ATM is for dividing all information into packets, each having a fixed length, that are referred to cells, and transmitting the information after a header necessary for a routing is added thereto, as described in a publication xe2x80x9cATM-LANxe2x80x9d (authored by Hiroshi Shimizu and Hiroshi Suzuki, published by Soft Research Center on Feb. 10, 1995), for example.
In this case, the cells are transmitted to objective ATM nodes or terminals by means of two kinds of logical connections of a virtual circuit and a virtual path. The virtual circuit is the connection which is set by allocating network resources (a route and a band) necessary for communication between a plurality of terminals by means of a signaling procedure every time a call is generated.
The virtual path is a logical transmission path which is semifixedly preset between predetermined nodes in accordance with prediction of a demand for how many traffics are expected between nodes, such as exchanges and transmission devices within an ATM network, for example, or a monitoring result of an amount of traffics that are actually transmitted therebetween. The virtual path is a connection which does not depend on network topology formed by actually connecting transmission lines, such as optical fibers and coaxial cables, to each other. This virtual path contains a plurality of virtual circuits.
On the other hand, between ATM transmitting or exchange devices on the basis of such cells, because of development of an optical fiber communication technology, fast cells are converted into optical signals and transmitted. Moreover, in recent years, in order to make a network have a more massive capacity, an optical communication node is being investigated, in which a wavelength dividing multiplex typed optical cross-connect device for multiplexing and transmitting a plurality of optical wavelengths in one optical fiber transmission line and, in a communication node, an optical signal is switched to another predetermined node as it is, and an ATM device are combined.
Conventionally, as such an optical communication node, there is an optical communication network node described in First Optoelectronics and Communications Conference (OECC ""96) Technical Digest, PD-1-5, pp. 10-11, 1996, xe2x80x9cOptical Cross-connect System Using Fixed-wave Length Converters To Avoid Wavelength Blockingxe2x80x9d, authored by Tatsuya, Shiragaki, Tomoki Kato, and Naoya Henmi.
FIG. 30 shows such an optical communication network node.
In addition, in explanation hereinafter, it is referred to a xe2x80x9cdropxe2x80x9d that a signal from a network constructed of the optical communication network node is sent to other networks and devices connected to a node of its own, as a matter of convenience. On the contrary, it is referred to an xe2x80x9cinsertxe2x80x9d that a signal from other networks and devices connected to the node of its own is sent to the network constructed of the optical communication network node. Moreover, it is referred to a xe2x80x9cpassxe2x80x9d that a signal from an adjacent optical communication network node within the network is sent to other optical communication network nodes.
Optical signals from wavelength multi-inputting optical transmission lines 4100-i (wherein i is 1 to M1, which is the same hereinafter.) are separated into optical signals having the n number of different wavelengths in wavelength de-multiplexers 4110-i, and thereafter, are input to an optical switch network 4130.
The optical switch network 4130 sends the optical signals from the wavelength de-multiplexers 4110-i to predetermined wavelength converters 4140-ixc2x7n or receiving interfaces 4160-j (wherein j is 1 to M2, which is the same hereinafter.).
Each of the wavelength converters 4140-(ixc2x7n-n+1) to 4140-ixc2x7n fixedly converts a wavelength of the input optical signal into xcex1 to xcexn.
Wavelength multiplexers 4111-i combines the optical signals from the wavelength converters 4140-(ixc2x7n-n+1) to 4140-ixc2x7n and sends the combined signals to wavelength multi-outputting optical transmission lines 4150-i, respectively.
On the other hand, cells of the optical signals from the optical switch network 4130 are converted into cells of electric signals in receiving interfaces 4160-k (wherein k is 1 to L, which is the same hereinafter.), respectively, and thereafter, are sent to an ATM switch 4170. And, cells of the optical signals from input optical transmission lines 4180-k are also converted into cells of electric signals in receiving interfaces 4161-k, respectively, and thereafter, are sent to an ATM switch 4170.
The ATM switch 4170 switches and outputs the input cells of the electric signals to predetermined transmitting interfaces 4162-j or 4163-k in accordance with headers thereof.
The switched cells of the electric signals are converted into cells of optical signals by the transmitting interfaces 4162-j, and thereafter, are sent to the optical switch network 4130.
The optical switch network 4130 also sends the cells of the optical signals from the transmitting interfaces 4162-j to the predetermined wavelength converters 4140-1 to 4140-M1xc2x7n or the receiving interfaces 4160-J.
Also, the switched cells of the electric signals are converted into cells of optical signals by the transmitting interfaces 4163-j, and thereafter, are sent to output optical transmission lines.
As described above, conventionally, the cells multiplied by the optical signals having an arbitrary wavelength, which are transmitted by the arbitrary wavelength multi-inputting optical transmission lines 4100-i, can be dropped into the arbitrary output optical transmission lines 4190-k. Also, the optical communication network node shown in FIG. 30 converts the cells from the arbitrary input optical transmission lines 4180-k into the optical signals having an arbitrary wavelength, and inserts the signals into the arbitrary wavelength multi-outputting optical transmission lines 4150-i.
Moreover, the optical communication network node shown in FIG. 30 can make the signals pass between the wavelength multi-inputting optical transmission lines 4100-i and the wavelength multi-outputting optical transmission lines 4150-i by converting the cells multiplied by the optical signals having an arbitrary wavelength, which are transmitted by the arbitrary wavelength multi-inputting optical transmission lines 4100-i, into the optical signals having an arbitrary wavelength, and inserting the signals into the arbitrary wavelength multi-outputting optical transmission lines 4150-i.
The above-mentioned conventional optical communication network node can conduct the drop and insert and further conduct the pass of the signals. However, this prior art has defects below.
First, in the above-mentioned prior art, two duplicate methods are used for conducting the conversion of a wavelength and passing the arbitrary optical signals between the wavelength multi-inputting optical transmission lines 4100-i and the wavelength multi-outputting optical transmission lines 4150-i. In other words, a method for realizing it by the optical switch network 4130 and the wavelength converters 4140-1 to 4140-M1xc2x7n, and a method for realizing it by converting the optical signals from the optical switch network 4130 into the electric signals, and thereafter, switching the signals by means of the ATM switch 4170, and using a path of the optical switch network 4130 and the wavelength converters 4140-1 to 4140-M1xc2x7n again are adopted.
Therefore, there is a defect that a large-scale optical switch network becomes to be needed and that it is difficult to realize a small-sized node and to lower a cost of the node. Particularly, in FIG. 30, in order to be able to output any signal on the wavelength multi-inputting optical transmission lines 4100-i and the input optical transmission lines 4180-k from anyone of the wavelength multi-outputting optical transmission lines 4150-i and the output optical transmission lines 4190-k, M2=(M1xc2x7n), and the number (2xc2x7M1xc2x7n)2 of cross points is necessary for the optical switch network 4130.
Also, since the above-mentioned two methods are overlapped to each other, there is a defect that the ATM switch with a large capacity becomes to be needed and that it is difficult to realize a small-sized node and to lower a cost of the node. Particularly, in FIG. 30, under a condition same as before, the ATM switch 4170 needs the number (M2+L)2=(M1xc2x7n+L)2 of cross points in order to switch the signals from the wavelength multi-inputting optical transmission lines 4100-i and the input optical transmission lines 4180-k.
Moreover, in the above-mentioned prior art, the optical switch network 4130 and the ATM switch 4170 are constructed in a hybrid manner. Accordingly, both the optical switch network 4130 and a self-routing switch of the ATM switch 4170 are not concurrently realized by one fast broad-band switch. Therefore, in FIG. 30, under the condition same as before, the number (2xc2x7M1xc2x7n)2 of cross points is necessary for the optical switch network 4130, and the number (M1xc2x7n+L)2 of cross points is necessary for the ATM switch 4170. In other words, since fast broad-band switches are used for both the optical switch network and the ATM switch, there is a defect that it is difficult to realize a small-sized node and to lower a cost of the node.
The present invention is made to solve the above-mentioned defects in the prior arts, and the objective of the present Invention is to provide an optical communication network node in which the required number of cross points of an optical switch network or a required capacity of an ATM switch is small, and accordingly, it is possible to realize a small-sized node and to lower a cost of the node.
Also, the objective of the present invention is to provide an optical communication network node in which the number of cross points unnecessary for an optical switch network which corresponds to a space dividing equivalent circuit is reduced, and it becomes to be possible to reduce hardware corresponding to the number of the unnecessary cross points, and it is possible to realize a small-sized device and moreover to lower a loss.
A first optical communication network node in accordance with the present invention includes first optical dropping means for dropping optical signals having arbitrary wavelengths of wavelength-multiplex optical signals which is multiplied by a wavelength, switching means for conducting switching of a signal after a drop by means of the above-described optical dropping means and an external input signal that is externally input, and first optical inserting means for joining a signal after switching by means of the above-described switching means to the above-described wavelength-multiplexing optical signals.
Also, the above-described switching means includes an input terminal to which a signal after drop by means of the above-described first optical dropping means and the above-described external input signal are input, a plurality of output terminals, and an ATM switch for outputting an input to the above-described input terminal to a desired one of the above-described plurality of output terminals.
Moreover, the above-described switching means includes second optical dropping means for further dropping optical signals having arbitrary wavelengths of the signal after the drop by means of the above-described first optical dropping means, a first input terminal to which the signal after drop by means of the above-described second optical dropping means is input, a plurality of first output terminals, a first ATM switch for outputting an input to the above-described first input terminal to a desired one of the above-described plurality of first output terminals, a second input terminal to which the above-described external input signal is input, a plurality of second output terminals, a second ATM switch for outputting an input to the above-described second input terminal to a desired one of the above-described plurality of second output terminals, and second optical inserting means for joining an output of the above-described second ATM switch to the signal after the drop by means of the above-described first optical dropping means.
And, the above-described switching means includes an input terminal to which the signal after the drop by means of the above-described first optical dropping means and the above-described external input signal are input, a plurality of output terminals, and an optical switch means for outputting an input to the above-described input terminal to a desired one of the above-described plurality of output terminals.
In short, in the present invention, since after dropping the optical signals having arbitrary wavelengths of wavelength-multiplex optical signals which is multiplied by a wavelength, the switching of the dropped signal and the external input signal is conducted, and the signal after the switching is joined to the wavelength-multiplex optical signals, the number of cross points necessary for an optical switch network is reduced and it is possible to realize a small-sized node and to lower a cost of the node.
Furthermore, in order to achieve the above-described objective, the second invention is an optical communication network node having both an ATM exchange function for exchanging ATM cells and an optical exchange function for exchanging optical signals as it is. The optical communication network node is constructed of a plurality of wavelength-multiplex receiving interfaces with buffers, having one input end and a plurality of output ends, for, after separating wavelength-multiplex optical signals input from the above-described one input end through each of a plurality of first input optical transmission lines into a plurality of optical signals having different wavelengths, outputting these plurality of optical signals as it is from each of the above-described plurality of output ends, or converting the above-described plurality of optical signals into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from each of the above-described plurality of output ends, a plurality of receiving interfaces with buffers, having one input end and one output end, for converting optical signals input from the above-described input end through each of a plurality of second input optical transmission lines into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from the above-described output end, a plurality of wavelength-multiplex transmitting interfaces, having a plurality of input ends and one output end, for converting each of optical signals on optical circuits, which are input from the above-described plurality of input ends, into an optical signal having a predetermined wavelength as it is, or for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals from the above-described plurality of input ends into electric signals, converting the electric signals into optical signals having the above-described predetermined wavelength, combining the plurality of converted optical signals having the above-described predetermined wavelength, outputting wavelength-multiplex optical signals from the above-described one output end, and transmitting the signals to a plurality of first output optical transmission lines, a plurality of transmitting interfaces, having one input end and one output end, for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals input from the above-described input end into electric signals, converting the electric signals into optical signals, outputting the optical signals from the above-described output end, and transmitting the signals to a plurality of second output optical transmission lines, a first optical switch network, having a plurality of input ends and a plurality of output ends which are connected to each output end of the above-described plurality of wavelength-multiplex receiving interfaces with the buffers, respectively, for setting the above-described predetermined optical circuits between the above-described plurality of predetermined input ends and output ends, or for exchanging the optical signals cell by cell under control by the above-described plurality of wavelength-multiplex receiving interfaces with the buffers, a second optical switch network, having a plurality of input ends and a plurality of output ends which are connected to each output end of the above-described plurality of receiving interfaces with the buffers, respectively, for exchanging the optical signals cell by cell under control by the above-described plurality of receiving interfaces with the buffers, and an optical distributing switch network, having a plurality of input ends and a plurality of output ends which are connected to the above-described first and second optical switch networks, for switching optical signals from the above-described plurality of input ends to the above-described output ends which are connected to the input ends of the above-described plurality of predetermined wavelength-multiplex transmitting interfaces and the input end of the above-described plurality of transmitting interfaces.
The third invention is an optical communication network node having both an ATM exchange function for exchanging ATM cells and an optical exchange function for exchanging optical signals as it is. The optical communication network node is constructed of a plurality of wavelength-multiplex receiving interfaces with buffers, having one input end and a plurality of output ends, for, after separating wavelength-multiplex optical signals input from the above-described one input end through each of a plurality of first input optical transmission lines into a plurality of optical signals having different wavelengths, outputting these plurality of optical signals as it is from each of the above-described plurality of output ends, or converting the above-described plurality of optical signals into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from each of the above-described plurality of output ends, a plurality of receiving interfaces with buffers, having one input end and one output end, for converting optical signals input from the above-described input end through each of a plurality of second input optical transmission lines into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from the above-described output end, a plurality of wavelength-multiplex transmitting interfaces, having a plurality of input ends and one output end, for converting each of optical signals on optical circuits, which are input from the above-described plurality of input ends, into an optical signal having a predetermined wavelength as it is, or for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals from the above-described plurality of input ends into electric signals, converting the electric signals into optical signals having the above-described predetermined wavelength, combining the plurality of converted optical signals having the above-described predetermined wavelength, outputting wavelength-multiplex optical signals from the above-described one output end, and transmitting the signals to a plurality of first output optical transmission lines, a plurality of transmitting interfaces, having one input end and one output end, for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals input from the above-described input end into electric signals, converting the electric signals into optical signals, outputting the optical signals from the above-described output end, and transmitting the signals to a plurality of second output optical transmission lines, first and second optical selective switch networks, having a plurality of input ends and a plurality of output ends, for selectively sending optical signals from the above-described plurality of input ends which are connected to the output ends of the above-described plurality of wavelength-multiplex receiving interfaces with the buffers and the output end of the above-described receiving interfaces with the buffers, respectively, to the above-described predetermined one or more than one output ends, a plurality of first optical switches, having a plurality of input ends and one output end which are connected to the output ends of the above-described first optical selective switch network, for setting predetermined optical circuits between the above-described plurality of predetermined input ends and one output end, or for exchanging the optical signals cell by cell under control by the above-described plurality of wavelength-multiplex receiving interfaces with the buffers, a plurality of second optical switches, having a plurality of input ends and one output end which are connected to the output ends of the above-described second optical selective switch network, for exchanging the optical signals cell by cell under control by the above-described plurality of receiving interfaces with the buffers, and an optical distributing switch network, having a plurality of input ends which are connected to output ends of the above-described first and second optical switches, and an output end which is connected to the input ends of the above-described plurality of wavelength-multiplex transmitting interfaces and the input end of the above-described transmitting interfaces, for switching optical signals from the above-described plurality of input ends to the above-described predetermined output end.
The fourth invention is an optical communication network node having both an ATM exchange function for exchanging ATM cells and an optical exchange function for exchanging optical signals as it is. The optical communication network node is constructed of a plurality of wavelength-multiplex receiving interfaces with buffers, having one input end and a plurality of output ends, for, after separating wavelength-multiplex optical signals input from the above-described one input end through each of a plurality of first input optical transmission lines into a plurality of optical signals having different wavelengths, outputting these plurality of optical signals as it is from each of the above-described plurality of output ends, or converting the above-described plurality of optical signals into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from each of the above-described plurality of output ends, a plurality of receiving interfaces with buffers, having one input end and one output end, for converting optical signals input from the above-described input end through each of a plurality of second input optical transmission lines into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from the above-described output end, a plurality of wavelength-multiplex transmitting interfaces, having a plurality of input ends and one output end, for converting each of optical signals on optical circuits, which are input from the above-described plurality of input ends, into optical signals having predetermined wavelengths as it is, or for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals from the above-described plurality of input ends into electric signals, converting the electric signals into optical signals having the above-described predetermined wavelengths, combining the plurality of converted optical signals having the above-described predetermined wavelengths, outputting wavelength-multiplex optical signals from the above-described one output end, and transmitting the signals to a plurality of first output optical transmission lines, a plurality of transmitting interfaces, having one input end and one output end, for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals input from the above-described input end into electric signals, converting the electric signals into optical signals, outputting the optical signals from the above-described output end, and transmitting the signals to a plurality of second output optical transmission lines, a first optical switch network, having a plurality of input ends and a plurality of output ends which are connected to each output end of the above-described wavelength-multiplex receiving interfaces, for setting the above-described predetermined optical circuits between the above-described plurality of predetermined input ends and output ends, or for exchanging the optical signals cell by cell under control by the above-described plurality of wavelength-multiplex receiving interfaces with the buffers and the above-described plurality of receiving interfaces with the buffers, a second optical switch network, having a plurality of input ends and a plurality of output ends which are connected to each output end of the above-described receiving interfaces, for exchanging the optical signals cell by cell under control by the above-described plurality of wavelength-multiplex receiving interfaces with the buffers and the above-described plurality of receiving interfaces with the buffers, and an optical distributing switch network, having a plurality of input ends which are connected to each output end of the above-described plurality of wavelength-multiplex receiving interfaces with the buffers and the above-described plurality of multiplex interfaces with the buffers, and a plurality of output ends which are connected to the input ends of the above-described first optical switch network and the inputs of the above-described second optical switch network, for switching optical signals from the above-described plurality of input ends to the above-described predetermined output ends.
The fifth invention is an optical communication network node having both an ATM exchange function for exchanging ATM cells and an optical exchange function for exchanging optical signals as it is. The optical communication network node is constructed of a plurality of wavelength-multiplex receiving interfaces with buffers, having one input end and a plurality of output ends, for, after separating wavelength-multiplex optical signals input from the above-described one input end through each of a plurality of first input optical transmission lines into a plurality of optical signals having different wavelengths, outputting these plurality of optical signals as it is from each of the above-described plurality of output ends, or converting the above-described plurality of optical signals into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from each of the above-described plurality of output ends, a plurality of receiving interfaces with buffers, having one input end and one output end, for converting optical signals input from the above-described input end through each of a plurality of second input optical transmission lines into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from the above-described output end, a plurality of wavelength-multiplex transmitting interfaces, having a plurality of input ends and one output end, for converting each of optical signals on optical circuits, which are input from the above-described plurality of input ends, into an optical signal having a predetermined wavelength as it is, or for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals from the above-described plurality of input ends into electric signals, converting the electric signals into optical signals having the above-described predetermined wavelength, combining the plurality of converted optical signals having the above-described predetermined wavelength, outputting wavelength-multiplex optical signals from the above-described one output end, and transmitting the signals to a plurality of first output optical transmission lines, a plurality of transmitting interfaces, having one input end and one output end, for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals input from the above-described input end into electric signals, converting the electric signals into optical signals, outputting the optical signals from the above-described output end, and transmitting the signals to a plurality of second output optical transmission lines, first and second optical selective switch networks, having a plurality of input ends and a plurality of output ends, for selectively dropping optical signals from the above-described plurality of input ends into the above-described predetermined one or more than one output ends, a plurality of first optical switches, having a plurality of input ends which are connected to each of the output ends of the above-described first optical selective switch network, and one output end which is connected to each input end of each of the above-described wavelength-multiplex receiving interfaces, for setting predetermined optical circuits between the above-described plurality of predetermined input ends and one output end, or for exchanging the optical signals cell by cell under control by the above-described plurality of wavelength-multiplex receiving interfaces with the buffers and the above-described plurality of receiving interfaces with the buffers, a plurality of second optical switches, having a plurality of input ends which are connected to the output ends of the above-described second optical selective switch network, and one output end, for exchanging the optical signals cell by cell under control by the above-described plurality of wavelength-multiplex receiving interfaces with the buffers and the above-described plurality of receiving interfaces with the buffers, and an optical distributing switch network, having a plurality of input ends which are connected to each of the output ends of the above-described plurality of wavelength-multiplex receiving interfaces with the buffers, and a plurality of output ends which are connected to each of the input ends of the above-described first optical selective switch network and the above-described second optical selective switch network, for switching optical signals from the above-described plurality of input ends to the above-described predetermined output ends.
The sixth invention is an optical communication network node having both an ATM exchange function for exchanging ATM cells and an optical exchange function for exchanging optical signals as it is. The optical communication network node is constructed of a plurality of wavelength-multiplex receiving interfaces with buffers, having one input end, a plurality of first output ends, and a plurality of second output ends, for, after separating wavelength-multiplex optical signals input from the above-described one input end through each of a plurality of first input optical transmission lines into a plurality of optical signals having different wavelengths, outputting these plurality of optical signals as it is from each of the above-described plurality of first output ends, or converting the above-described plurality of optical signals into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from each of the above-described plurality of second output ends, a plurality of receiving interfaces with buffers, having one input end and one output end, for converting optical signals input from the above-described input end through each of a plurality of second input optical transmission lines into electric signals, temporarily storing ATM cells in the buffers, which are taken out from transmission frames, and after processing headers of the ATM cells output from the above-described buffers, converting the electric signals into optical signals and outputting the optical signals from the above-described output end, a plurality of wavelength-multiplex transmitting interfaces, having a plurality of first input ends, a plurality of second input ends, and one output end, for converting each of optical signals on optical circuits, which are input from the above-described plurality of first input ends, into an optical signal having a predetermined wavelength as it is, or for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals from the above-described plurality of second input ends into electric signals, converting the electric signals into optical signals having the above-described predetermined wavelength, combining the plurality of converted optical signals having the above-described predetermined wavelength, outputting wavelength-multiplex optical signals from the above-described one output end, and transmitting the signals to a plurality of first output optical transmission lines, a plurality of transmitting interfaces, having one input end and one output end, for, after storing ATM cells in transmission frames, which are taken out by converting each of optical signals input from the above-described input end into electric signals, converting the electric signals into optical signals, outputting the optical signals from the above-described output end to the plurality of first output optical transmission lines, a first optical switch network, having a plurality of input ends which are connected to the first output ends of the above-described wavelength-multiplex receiving interfaces with the buffers, and an output end which is connected to the input end of the above-described plurality of wavelength-multiplex receiving interfaces, for setting the above-described predetermined optical circuits between the above-described plurality of predetermined input ends and output end, a second optical switch network, having a plurality of input ends which are connected to the second output ends of the above-described wavelength-multiplex receiving interfaces with buffers, and a plurality of output ends which are connected to the input end of the above-described transmitting interfaces through an optical combiner, for exchanging the optical signals cell by cell under control by the above-described plurality of wavelength-multiplex receiving interfaces with the buffers, a third optical switch network, having a plurality of input ends which are connected to the output end of the above-described plurality of receiving interfaces with the buffers through an optical separator, and a plurality of output ends which are connected to the input end of the above-described transmitting interfaces through the above-described optical combiner, for exchanging the optical signals cell by cell under control by the above-described plurality of receiving interfaces with the buffers, and a fourth optical switch network, having a plurality of input ends which are connected to the output end of the above-described plurality of receiving interfaces with the buffers through the above-described optical separator, and a plurality of output ends which are connected to each of the second input ends of the above-described plurality of wavelength-multiplex transmitting interfaces, for exchanging the optical signals cell by cell under control by the above-described plurality of receiving interfaces with the buffers.
In accordance with the optical communication network node of the second invention, in case that the wavelength-multiplex optical signals are input to the plurality of wavelength-multiplex receiving interfaces with buffers through the plurality of first input optical transmission lines, after these wavelength-multiplex optical signals are separated into a plurality of optical signals having different wavelengths, the optical signals are output as it is to the first optical switch network, or the ATM cells which are taken out in the transmission frames by converting the wavelength-multiplex optical signals into electric signals are temporarily stored in the buffers, and after the headers of the ATM cells output from the buffers are processed, the electric signals are converted into optical signals and the optical signals are output to the first optical switch network.
Also, in case that the optical signals are input to the plurality of receiving interfaces with buffers through the second optical switch network, these receiving interfaces with buffers temporarily store the ATM cells in the buffers, which are taken out from the transmission frames by converting the optical signals into electric signals, and after processing the headers of the ATM cells taken out from these buffers, convert the electric signals into optical signals and output the optical signals to the second optical switch network.
In the first optical switch network, the predetermined optical circuits are set between the predetermined input ends and output ends, or the optical signals are exchanged cell by cell under control by the wavelength-multiplex interfaces with the buffers, and the exchanged signals are output to the optical distributing switch network.
In the second optical switch network, the optical signals are exchanged cell by cell under control by the plurality of receiving interfaces with the buffers, and the exchanged signals are output to the optical distributing switch network.
The optical distributing switch network switches and distributes the optical signals input from the first optical switch network and the second optical switch network to the plurality of predetermined wavelength-multiplex transmitting interfaces and the plurality of the transmitting interfaces.
In the plurality of wavelength-multiplex transmitting interfaces, the input optical signals are converted into an optical signal with a predetermined wavelength as it is, and the optical signal is output to the plurality of first output optical transmission lines, or after the ATM cells are stored in the transmission frames, which are taken out by converting the input optical signals into electric signals, the electric signals are converted into optical signals, the plurality of converted optical signals are combined, and the combined signals are output to the plurality of first output optical transmission lines.
Furthermore, in the plurality of transmitting interfaces, after the ATM cells are stored in the transmission frames, which are taken out by converting the optical signals input from the optical distributing switch network into electric signals, the electric signals are converted into optical signals, and the optical signals are output to the plurality of second output optical transmission lines.
Also, in accordance with the optical communication network node of the third invention, after the wavelength-multiplex optical signals input to the wavelength-multiplex receiving interfaces with buffers through the first input optical transmission lines into a plurality of optical signals having different wavelengths, the optical signals are output as it is, or the ATM cells are temporarily stored in the buffers, which are taken out from the transmission frames by converting the optical signals into electric signals, and after the headers of the ATM cells output from the buffers are processed, the electric signals are converted into optical signals and the optical signals are output, and in the first optical selective switch network, these optical signals are selectively separated into the output ends and sent to the first optical switches, and in the first optical switches, the optical signals are output to a predetermined optical circuits or are exchanged cell by cell under control by the wavelength-multiplex receiving interfaces with the buffers and output to the optical distributing switch network.
On the other hand, in case that the optical signals are input to the receiving interfaces with buffers through the second input optical transmission lines, after the ATM cells are temporarily stored in the buffers, which are taken out from the transmission frames by converting the optical signals into electric signals, the headers of the ATM cells output from the buffers are processed and the electric signals are converted into optical signals again, and the optical signals are output to the second optical selective switch network.
In the second optical selective switch network, these optical signals are selectively output to predetermined output ends and sent to the second optical switches, and in the second optical switches, these optical signals are exchanged cell by cell under control by the receiving interfaces with the buffers, and are output to the optical distributing switch network.
In the optical distributing switch network, the optical signals from the first and second optical switches are distributed to the wavelength-multiplex transmitting interfaces and the transmitting interfaces.
In the wavelength-multiplex transmitting interfaces, the optical signals are converted into an optical signal having a predetermined wavelength, or after the ATM cells are stored in the transmission frames, which are taken out by converting the optical signals into electric signals, the electric signals are converted into optical signals having the predetermined wavelength, wavelength-multiplex optical signals in which the converted optical signals are combined, and are output to the wavelength-multiplex output transmission lines.
In the transmitting interfaces, after the ATM cells are stored in the transmission frames, which are taken out by converting the input optical signals into electric signals, the electric signals are converted into optical signals, and the optical signals are output to the second output optical transmission lines.
Moreover, in accordance with the optical communication network node of the fourth invention, after, in the wavelength-multiplex receiving interfaces with buffers, the optical signals input through the first input optical transmission lines are separated into a plurality of optical signals having different wavelengths, the optical signals are output as it is, or after the ATM cells are temporarily stored in the buffers, which are taken out from the transmission frames by converting the optical signals into electric signals, the headers of the ATM cells output from the buffers are processed, and thereafter, the electric signals are converted into optical signals and the optical signals are output to the optical distributing switch network.
In the receiving interfaces with buffers, in case that the optical signals are input through the second input optical transmission lines, the headers of the ATM cells are processed, which are taken out from the transmission frames by converting these optical signals into electric signals, and the electric signals are converted into optical signals, and the optical signals are output to the optical distributing switch network.
The optical distributing switch network switches and sends the optical signals input from the wavelength-multiplex receiving interfaces with the buffers and the receiving interfaces with the buffers to the predetermined first and second optical switch networks, and the first and second optical switch networks set the respective predetermined optical circuits, or exchange the optical signals cell by cell under control by the wavelength-multiplex receiving interfaces with the buffers and the receiving interfaces with the buffers, and output the optical signals to the wavelength-multiplex receiving interfaces and the receiving interfaces.
The wavelength-multiplex transmitting interfaces convert the optical signals into an optical signal having a predetermined wavelength, or after storing the ATM cells in the transmission frames, which are taken out by converting each of optical signals into electric signals, convert the electric signals into optical signals having the predetermined wavelength, combine the plurality of optical signals and output wavelength-multiplex optical signals to the wavelength-multiplex output optical transmission lines.
In the transmitting interfaces, after the ATM cells are stored in the transmission frames, which are taken out by converting the optical signals from the second optical switch network into electric signals, the electric signals are converted into optical signals, and the optical signals are output to the output optical transmission lines.
In accordance with the optical communication network node of the fifth invention, the wavelength-multiplex optical signals input to the wavelength-multiplex receiving interfaces with buffers through the first input optical transmission lines are output as optical signals as it is, which are separated into a plurality of optical signals having different wavelengths, or the ATM cells are temporarily stored in the buffers, which are taken out from the transmission frames by converting these optical signals into electric signals, and after the headers of the ATM cells output from the buffers is processed, the electric signals are converted into optical signals, and the optical signals are output to the optical distributing switch network.
Also, the optical signals input to the receiving interfaces with buffers through the second input optical transmission lines are converted into electric signals, and after the headers of the ATM cells, which are taken out from the transmission frames are processed, the electric signals are converted into optical signals, and the optical signals are output to the optical distributing switch network.
The optical distributing switch network switches and distributes the optical signals input from the wavelength-multiplex receiving interfaces with the buffers and the receiving interfaces with the buffers to the predetermined first and second optical selective switch networks, and in the first and second optical selective switch networks, the optical signals are selected and output to the first optical switches and the second optical switches, respectively.
The first optical switches and the second optical switches set predetermined optical circuits, or exchange the optical signals cell by cell under control by the wavelength-multiplex receiving interfaces with the buffers and the receiving interfaces with the buffers, and transmit the optical signals to the wavelength-multiplex transmitting interfaces and the transmitting interfaces.
The wavelength-multiplex transmitting interfaces convert the optical signals input from the first optical switches into an optical signal having a predetermined wavelength, or after storing the ATM cells in the transmission frames, which are taken out by converting each of the optical signals into electric signals, convert the electric signals into optical signals having the predetermined wavelength, and thereafter, output the optical signals to wavelength-multiplex output optical transmission lines.
In the transmitting interfaces, after the ATM cells are stored in the transmission frames, which are taken out by converting the optical signals input from the second optical switches into electric signals, the electric signals are converted into optical signals, and the optical signals are transmitted to the second output optical transmission lines.
In accordance with the optical communication network node of the sixth invention, the wavelength-multiplex optical signals input to the wavelength-multiplex receiving interfaces with buffers through the first input optical transmission lines are separated into a plurality of optical signals having different wavelengths, and the plurality of optical signals are output from the first output ends to the first optical switch network, or the ATM cells are temporarily stored in the buffers, which are taken out from the transmission frames by converting the plurality of optical signals into electric signals, and after the headers of the ATM cells output from the buffers are processed, the electric signals are converted into optical signals, and the optical signals are output from the second output ends to the second optical switch network.
In case that the optical signals are input to the receiving interfaces with buffers through the second input optical transmission lines, these optical signals are converted into electric signals, and the ATM cells which are taken out from the transmission frames are temporarily stored in the buffers, and after the headers of the ATM cells taken out from the buffers are processed, the electric signals are converted into optical signals, and the optical signals are output to the third and fourth optical switch networks through the optical separator.
In the first optical switch network, predetermined optical circuits are set, and the optical signals input from the wavelength-multiplex receiving interfaces with the buffer are transmitted to the wavelength-multiplex transmitting interfaces.
The optical signals output from the receiving interfaces with the buffer are input to the fourth optical switch network through the optical separator, and in the fourth optical switch network, the optical signals are exchanged cell by cell and output to the wavelength-multiplex transmitting interfaces.
The wavelength-multiplex transmitting interfaces convert the optical signals from the first optical switch network into an optical signal having a predetermined wavelength, or after storing the ATM cells in the transmission frames, which are taken out by converting the optical signals from the fourth optical switch network into electric signals, convert the electric signals into optical signals having the predetermined wavelength, combine the optical signals, and transmit wavelength-multiplex signals to the first output optical transmission lines.
Also, the optical signals input to the second optical switch network from the second output ends of the wavelength-multiplex receiving interfaces with buffers are exchanged cell by cell and are input to the transmitting interfaces through the optical combiner, and the optical signals input to the third optical switch network from the receiving interfaces with buffers through the optical separator are exchanged cell by cell and in the optical combiner, the optical signals are joined to the optical signals from the second optical switch network, and are input to the transmitting interfaces.
In the transmitting interfaces, after the ATM cells are stored in the transmission frames, which are taken out by converting the input optical signals into electric signals, the electric signals are converted into optical signals, and the optical signals are output to the second output optical transmission lines.